Tow glider release



Aug. 29, 1950 N. D. AsHwooD TOW GLIDER RELEASE 2 Sheets-Sheet 1 Filed Aug. 25, 1949 INVENTOR Norma/'7 0. AS/IWOOOI Aug. 29, 1950 N.-D. ASHWOOD TOW .GLIDER RELEASE 2 Sheets-Sheet 2 llllll l MHH- 1 21:.

Fil ed. Aug. 25, 1949 INVENTOR Norman D. fls/m ood m Q 9 Q ATTORNEY Patented Aug. 29, 1950 Towerin -assures Norman D: Ashwood; Victoria British' Golumbia, Canada ApplicationAugust 23, wife, Serial N6; 11 118 65 1'- g This invention remtes tea-mechan sm incorpm rated in a glider: for releasing the glider. F Anobject of the invention i'sfitlie' provision of 'mechanisms in gli'd'ers for' releasing the gliders automatically and in' succession a t-"prescribed intervals, the releasing 'mechani's'rn uavin as its principal elements, a; 1on3 bolt tlireade'd into 1 a nut fixed against rotation irr th'e bo'dy' of the glider a'nd a Vane or"proloeller"secured 'todnend of'tlie' bolt and normally he'ldag'ai'nst rotation bya pin which is held 'in an operationby'* a tow- 1ihe -attached"to' the glider and pulling a? load, slack in the towline causing the releas-dfftlie Another'obje'ct of the inventionis tlie prdvision ofa' mechanism in a glider being towed bya pmfie for releasing'the'glider automaticallywhen a bolt 'threadedinto a nut fixed'in the'body of 'theglider is rever's'el'y' rotated by vanes" oi" a propeller .operatedb'y' air currents when the" glider is drawn through the air; a' reciprocating rod retaining the vanes or propeller" normallyagainst" rotation until withdrawn by a lever which is rock'ewby'the action 'ofta spring when the pull-"onthespring is relaxed;

.A" further obj ect" of the inventiomis'" the provi "sion of a" mechanism for? releasing a "glider rro'm 31 towing" plane when a" slack occurs in a towline connected between the" first glider-'and.='-a second glider, the .mechanisni 'in ther second glider. said glider'in arl mnceiof'the first glider, variations in the mechanismsr'in' a series 'of'gliders causing thef'gliders'tor'be releasedat different intervals oftinie.

This invention is best understood fr'oma c'onsideration of the following detailed descrilitibn taken" in conjunction with the accompanying drawings; forming part of the" specification, nevertheless; it must be" borne in mind. thatthe invention is not confined tothe'disclosure'but is susceptible of such changesandtmodifications as shall define no material departure from the salient features of the invention expressed in the appended claims;-

In'the drawings:

Figure 1 is a longitudinalsideviewof'wtowing plane and a pair of gliders connected -togetlierby my improved releasing towline;

' Figure 2 is an enlarged longitudinal vertical section taken through the longitudinalaxis of a glider;

Figure 3 is agreatly enlarged longitudinal vertical section of the releasing mechanism in a glider, takenalong the line 3+3 of 'FigureI4;

Figure 4 is a transverseuverticallsection of-the all) releasing mechanism taken along the li'ri'e 4 4 ofTig-ure 3 Figure 5 is a greatly enlargedlongitudinal vertiea'l section of 'a' cushioning device incorpo'- rated the towline; and

' Figure 6"is a fragmentary vertical section of the tail of the towing plane showing'th'e connedtions for the-towline.

Referring more particularly to'the drawings; H1

designates a towing plane to'which are'co'nne'cted two ormo'reglidersl land f2 by means of towlinese iii-and Ma The towlines' are ,identical'in co"nstruc'tioni Wheri the'line I3 is released from th glider? l'fl 'it'is'carrie'd by the planel0. When 'th'ef-line l'4 is' released from the" glider l'2 'f it is carried by I the glider l1.

Each tcwline includes as its main element" a (Figures 1' and-"5) is incorporated in" the center 'ofi'the' wireiortcord [5. The" rin'gI'IS' has an inte'grallwire' or sliankl'ni connectedwith a swivel 2|. A wire 22" (Figures 1-, 2and6l' connects the swiveliwith'ranrseye 23 which" in turn is'received by'a'safetyhookifl 'on the plane? 10. Itwill be tionionthe towingplane" NY. The inner end" of the wire 25." is''' attached to a brace bar" or partitibn" ZBfZifl the Plii'ne.

The safety catch" 24a: on the towlirie Hf is securedlto ast'ifi'wire'or thin rod 39" Figu're2) I which enters a bearing opening in the outer end of a cylin'd'ei'e l; A=pistonj 3i! is rigid" with the toor' formed integrally with the inner'e'nd 'oftlie cylinderand theperiphery' of'sai'ol name is connetted a't' "34- tothe inner surface of thetaifo'f theglider 'll r The tail" of theglide'r I? is similarly equipped so that a: third gliderimay 'be attached tbttlfl''gl-ider l2 i fi'desired'.

A machine screwor bolt 35 is threaded onto a n'ut '36 (Figures? and 4) which has a knurledo'r roughiouter surface fitted frictionall'y into aligned passage in tlie' abuttingsends of sections and 33 of a body formed of some light material; such as 'a well known plastic; aluminum or Plexiglas. E-shellfifl neatly receivesthe sections and a screw shell 40.

end of the section 37. ,A' nut rigidly onthe screw 35. I

tratediin Figures Z-and 3.

secured to the shell may be employed for fixing the section 31 more firmly to said shell. The

front end of the section 31 and the shell are a tapered; Flanges 43 fasten the shell to the inner walls of the fuselage of the gliders. A plug 45 threaded into the rear end of the shell closes said end. A sleeve 46 formed integrally with or secured to the bottom of said shell forms a guide for a rod 41. The longitudinal centers of'the sections are cored as shown at 48 and 49 to provide passages for the free longitudinal movement of the sore 35 as will be explained presently.

Vanes or a propeller 58 (Figure 3) has a hub provided with a threaded horizontal passage to receive the screw 35. The outer end of the hub abuts a head on the screw. A shank 52 projecting outwardly from the head has. an eye 53 received by the eye 23 on the outer edge of the towline. The rear of the vanes are so arranged that they will be spaced from tapered end of the It; will be notedthat the free end of the rod 41 will project into the path of the vanes and will retain the same. against rotation until said rod is withdrawn. When a propeller is employed, it will be necessary to shorten thetapered 54 fixes the vanes An operating mechanism for; the rod 41 is illus- The nut 45 carries a pair of parallel cars 55 projecting rearwardly therefrom. An axle 56 is mounted in the free ends of the ears and a lever 51 is rockable on said axle. A link 58 has one end pivoted at 59 on the lower end of the lever. The other end of said link has pivotal connections at 60 with the rear end of j the stop rod 4?. The link compensates'for oscillating movements of the lever. A stiif wire has one end attached pivotally to the upper end of :the lever 51; An angular portion 62 of the wire locates the main portion of the wire along the longitudinal'axis of the glider so that portion may be secured to the piston 32 which-is acted on by a spring 53 in the cylinder 3|; J

The cushioning means 18 is illustrated more particularly in Figure 5 and it includes a cylinder 65 closed at both ends. One end has a removable cap 65 so thatpistons 51 and 68 may be inserted into said'ipylinder together with the respective ID. The screws in the gliders I I and I2 may have 7 7 said screws out of the nuts 36 there would be a springs 69 and T0. Arod 'H is securedto'the "piston 61 and after passingthrough an opening in cap 65 terminates in an eye to which one section of the cord I5 is bound. A rod 13 is rigid with the piston 68 andterminates" in aneye 14 located exteriorly of the other'end' of the cylinder.

The rod protrudes through an opening in the adjacent end of the cylinder. The cushioning deagainst the tension of the spring 63 (Figure 2) and the free end of the rod 4'! (Figure 3) will As soon as so that the air currents will cause the vanes to rotate.

The screws are rotated by the vanes in such a manner that they will be released from the nuts '36 and the gliders 'will be freeof the plane vice eases the strain on the towlines and gliders I during a take-01f and when the plane and gliders gliders and it is desired to release the gliders, .the speed of the plane is reduced whence the towline will become slack. During normal pulling of the gliders, the wires 6I-wil1 remain taut tendency to twist the towlines. However, the

,swivels permit the eyes 53 to turn the eyes 23 but such rotation is not transmitted beyond said swivels.

'Any number of gliders may be towed. However, the last glider in the series will be released first because the vanes will start rotating as soon as the gliders are in flight. This is due to the fact that no pull is exerted on the safety catch 24a and -the rod l'l: will be out of engagement with the vanes 5'0since the spring 63 will have forced the wire fii-inwardly-to rock the lever to the dotted line position shown in Figure 2. It must be borne in mind that the slack in the towlines has no eflect on the last glider in the series since no pull is exerted on the safety catch 24a projecting from the tail of said glider. r

It should be understood that the pitch of the threads of the bolt 35 may be varied to increase or decrease the time at which aglider is released or a variance in the angle of the propeller blades will obtain the same effect.

What I claim:

1. A releasable mechanism incorporated in a glider comprising a nut fixed against rotation in the body; of the glider, a screw threaded into the nut in one; direction in the nut, one end of the screw projecting beyond 'the'nose of the glider, vanes secured to the projecting end of the screw, a rod having an end. extending into the path of the vanes for retaining said vanes against rotation, a lever rockably mounted in the glider and having pivotal connections with the rod, a spring in the tailof the glider, means acted on by the spring and connected with the lever for rocking (the lever in anoperative direction to release the rod from the vanes, the spring being retained in an inoperative position by a releasable load to pre- "vent rocking of the lever until the load is released,

the released vanes rotating the screw when the glider is soaring through the air to turn the screw out of the nut and a flexible towline connecting the glider to a towingplane. 7

;2. A releasable mechanism'incorporated in a glider comprising a nut fixed against rotation in the body of the glider, a screw threaded into the nut in one direction in the nut, one end of the screw projecting beyond the nose of the glider, vanes secured to the projecting end of the screw, a rod'having an end extending into the path of the vanes for retaining said'vanes against rotation, a coil spring tending to release the rod from the vanes, means causing compression of the spring to prevent release of the rod and including a towline attached at one end to said means, the other end of said line being connected to a load, slack in the towline relieving compression of the spring, the released vanes rotating the screw in a direction'to withdraw the screw from the nut. 3. A releasable mechanism incorporated in a glider comprising a nut fixed against rotation in the body of the glider, a screw threaded into the nut in one direction in. the nut,'one end of the screw projecting'beyond the nose of the glider,

from the vanes, a slack in the last mentioned towline releasing the spring for withdrawing the rod.

4. A releasable mechanism incorporated in a glider comprising a nut fixed against rotation in the body of the glider, a screw threaded into the nut in one direction in the nut, one end of the 15 screw projecting beyond the nose of the glider, vanes secured to the projecting end of the screw, a rod having an end extending into the path of the vanes for retaining said vanes against rotation, a spring urging the rod towards release, a flexible means connected between the spring and a load extending rearwardly from the tail of the glider for retaining the spring against movement, a slack in the flexible means releasing the spring to free the rod from the vanes 50 that the vanes will rotate the screw and withdraw said screw from the nut.

NORMAN D. ASHWOOD.

No references cited. 

